| Urinary calculi disease is one of the most common disease in urology. In southern part of our country, patients with urinary tract calculi are the majority of in-hospital patients of urologic department and constitute above 30% of urologic in-hospital patients. In the development of medical technology, endourological management of calculi of different urinary parts is becoming the standard therapy at large medical centers and community-based hospitals worldwide. Various endourological treatment options are available for different urinary calculi, including extracorporeal shock wave lithotripsy(ESWL), percutaneous nephroscopic lithotripsy, laparoscopic ureterolithotomy, retrograde cystoscopy and ureteroscopy using defferent intracorporeal lithotripsy. Refinements in endoscopic technology, combined with advances in intracorporeal lithotripsy, currently allow management of calculi along the entire urinary course of the urinary tract endoscopically. Especially flexible ureteroscopy has improved the successful treatment of upper ureteral and renal calculi and offers an alternative in the treatment of these stones. Intracorporeal lithotriptors can be categorized as mechanical, spark gap, high-energy ultrasonic waves and lasers, of which each has advantages and limitations. Urologist are looking for suitable intracorporeal lithotriptor for management of urinary calculi, efficiency and safe.For all of these intracorporeal lithotriptors, it is ideal to destroy calculi efficiency,without expanding the orifice of the ureter, and without applying any external force tothe ureteral wall in using ureterorenoscopy. Lasers are ideally suited for minimally invasive lithotripsy,since the diameter of the laser fiber is small and the aperture of the working channel can be minimized. It is possible by utilizing a laser to miniaturize the size of the ureteroscope itself. So more urologists think highly of laser lithotriptors. The hoImium:YAG laser is a solid state laser system. The active medium is the rare earth element holmium combined with an yttrium-aluminum-garnet crystal. The laser operates at a wavelength of 2,140nm, which is in the near infrared portion of the electromagnetic spectrum and, therefore is invisible to the human eye. The unique wavelength determines the useful clinical properties that distinguish it from other commonly used medical lasers. Because the 2,140nm wavelength can be transmitted through silica quartz fibers, the holmium laser is especially suited for endoscopic procedures. Fibers used to transmit holmium laser energy are well suited for flexible and rigid endoscopes. At a wavelength of 2,140nm, the laser pulse is strongly absorbed by water. Thus, in human tissue most laser energy is contained superficially, providing the holmium laser with excellent cutting and tissue ablation properties. The studies of efficacy have shown that the holmium:YAG laser cuts and incises soft urinary tissue with precision and fragments all types of urinary calculi, which is a distinct advantage over the other lasers used in urology. Holmium lasers emit at 2,140nm. This wavelength band is absorbed well by water. All stones(including cystine calculi) will absorb this wavelength well independently of stone color both because of the water within the stone and the water on the stone surface. It vaporizes surrounding fluid and fluid in pores in the surface of the stone and produces a cavitation bubble. The pulse duration(250us) also results in photoacoustic effect that aid stone fragmentation and destruction of bonds in stone matrix. In 1995, Bagley first reported their experience in clinical management of urinary calculi by holmium lithotripsy. Because holmium laser can fragment all types of urinary calculi, suitable for endoscopic use, minimize ureteral wall trauma in stone fragmentation. Holmium lithotriptor is wildly used by urologists in management of urinary calculi. In our country holmium laser lithotripsy for urinary stones was developed just in the recentyears and it has not been widely used. Although...
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